Soft tissue repair material fixation apparatus and method

ABSTRACT

An apparatus for use in affixing material to a location under repair includes a material retention member and an anchor. The anchor is configured to be inserted into a cavity in bone tissue, the anchor having a first end and a second end. The anchor also includes one or more raised ribs. The material retention member extends radially from the first end of the anchor in a plurality of directions, the material retention member including at least one contact surface adapted to exert a retention force on material that is interposed between the material retention device and the bone tissue.

This application is a continuation of application Ser. No. 09/494,741,filed on Jan. 28, 2000 now U.S. Pat. No. 6,508,821.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to assemblies that are used in the repairof bone and/or cartilage, and more particularly, to such assemblies aswell as methods and apparatus for affixing repair material to boneand/or cartilage.

In the practice of orthopedics it is known to introduce repair materialto a bone and/or cartilage requiring therapeutic tissue repair. Suchrepair material may include cartilage replacement material. In general,the repair materials currently employed in such circumstances includeany of a collagen mix, a synthetic scaffold, a biologic scaffold, andnonwoven or woven fibers. In some cases, the repair material may includeor comprise a flap of the damaged cartilage.

Currently, such repair materials are introduced to the location underrepair and secured in the area via stapling to the bone tissue or viasuturing. There is a need, however for a more secure method of affixingrepair material to the location of the body under cartilage and/or bonerepair.

The present invention fulfills the above needs, as well as others, byproviding an apparatus for securing soft tissue repair material in alocation in the body under repair. The apparatus includes an anchor anda material retention member that extends radially in a plurality ofdirections from the anchor and is adapted to exert a retaining force onthe soft tissue repair material that urges or retains the materialagainst bone tissue in the location under repair. One benefit of thepresent invention is that the anchor provides a mechanism by which theretention member may be anchored in place, allowing the retention memberto retain the soft tissue repair material.

In a first embodiment of the present invention, an apparatus for use inaffixing material to a location under repair includes a materialretention member and an anchor. The anchor is configured to be insertedinto a cavity in bone tissue, the anchor having a first end and a secondend. The anchor also includes one or more raised ribs. The materialretention member extends radially from the first end of the anchor in aplurality of directions, the material retention member including atleast one contact surface adapted to exert a retention force on materialthat is interposed between the material retention device and the bonetissue.

In a second embodiment of the present invention, a method of effectingtherapeutic reparation of a location of the body includes a first stepdisposing soft tissue repair material in the location of the body. Themethod also includes the step of securing an anchor of a fixation deviceinto a cavity in bone tissue in the vicinity of the location, the anchorhaving a first end and a second end and further comprising a materialretention member extending radially from the anchor in a plurality ofdirections. The anchor is secured into the cavity such that at least onecontact surface of the material retention member engages a portion ofthe soft tissue repair material that is interposed between the materialretention device and the bone tissue.

The above-described features and advantages, as well as others, willbecome more readily apparent to those of ordinary skill in the art byreference to the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a first exemplary embodiment of afixation device according to the present invention;

FIG. 2 shows a side cutaway view of a first exemplary embodiment of anassembly for effecting therapeutic repairs that includes the fixationdevice of FIG. 1 shown implemented in a location of a body that is underrepair;

FIG. 3 shows a top plan view of a second exemplary embodiment of anassembly for affecting therapeutic repairs;

FIG. 4 shows a side plan view of a second exemplary embodiment of afixation device according to the present invention;

FIG. 5 shows a side plan view of a third exemplary embodiment of afixation device according to the present invention;

FIG. 6 shows a side plan view of a fourth exemplary embodiment of afixation device according to the present invention;

FIG. 7 shows a side plan view of a fifth exemplary embodiment of afixation device according to the present invention;

FIG. 8 shows a side plan view of a sixth exemplary embodiment of afixation device according to the present invention;

FIG. 9 shows a perspective view of a seventh exemplary embodiment of afixation device according to the present invention;

FIG. 10 shows a side plan view of an eighth exemplary embodiment of afixation device according to the present invention; and

FIG. 11 shows a side cutaway view of a third exemplary embodiment of anassembly for effecting therapeutic repairs that includes the fixationdevice of FIG. 10 shown implemented in a location of a body that isunder repair.

DETAILED DESCRIPTION

FIG. 1 shows a perspective view of a first exemplary embodiment of afixation device 10 according to the present invention. In general, thefixation device 10 includes an anchor 12 and a material retention member14. The anchor 12 has a first end 16 and a second end 18. The materialretention member 14 extends radially in a plurality of directions fromthe first end 16 of the anchor 12 and is configured to exert a retentionforce on material that is interposed between the material retentionmember 14 and bone tissue of a body. (See generally FIG. 2, discussedbelow). The fixation device 10 is preferably composed of polydioxanon,also referred to as PDS.

In further detail, the anchor 12 of the exemplary embodiment of FIG. 1is in the form of a shaft and includes a cylindrical center portion 20that has a plurality of raised ribs 22. Each of the plurality of raisedribs 22 extend circumferentially around the cylindrical center portion20. The anchor 12 tapers inward from the cylindrical center portion 20to the second end 18. The anchor 12 is cannulated, thereby forming achannel 24 within the anchor 12 that runs essentially the length of theanchor 12.

The material retention member 14 of the exemplary embodiment of FIG. 1includes a plurality of spokes 26, 28, 30 and 32 that extend radiallyfrom the anchor in a plurality of directions. The spoke 26 includes acontact surface 34 that contacts the repair material (see FIG. 2) toexert downward force thereon. The contact surface 34 further includes aspike 36 extending axially therefrom. Each of the other spokes 28, 30and 32 has a substantially similar structure.

A generalized discussion of the use of the retention device 10 ineffecting therapeutic repair of a location in the body is providedbelow. FIGS. 1 and 2 will be referenced in the generalized discussion ofthe use of the retention device 10.

FIG. 2 shows a side cutaway view of a first exemplary embodiment of anassembly 40 for effecting therapeutic repairs that includes the fixationdevice 10 of FIG. 1. The assembly 40 is shown implemented in a location42 of a body that is under repair. In general, the location 42 of thebody, which may be human or otherwise, is in the vicinity of bonetissue. In the preferred embodiment of the present, the invention, theassembly 40 is used to effect therapeutic repairs to locations near bonetissue that have damaged or removed cartilage. Typically, damaged orremoved cartilage occurs near bone joints such as, for example, in thevicinity of a human knee, ankle or wrist.

The repair assembly 40 includes a soft tissue repair material 44, whichin the preferred embodiment is a matrix, that is secured to bone tissue46 in the location 42 that is exposed due to cartilage removal ordamage. The repair material 44 is secured to the bone tissue 46 at leastin part by the fixation device 10. To this end, the material retentionmember 14 is positioned to exert a retention force on the repairmaterial in the direction toward the bone tissue 46.

It will be noted that the repair material 44 may be secured to the bonetissue by fixation devices other than the fixation device 10 of FIGS. 1and 2. Such other fixation devices may include those shown in FIGS. 4through 10 or other suitable alternative devices that include an anchorand a material retention member that extends in a plurality ofdirections from the anchor. Such devices would have at least some of thebenefits of the invention provided herein, including retention strengthand reliability.

The soft tissue repair material 44 may be composed of any one of aplurality of materials known to be used for cartilage repair. Suchmaterials include, but are not limited to, a collagen matrix, asynthetic scaffold, a biologic scaffold, nonwoven fibers or wovenfibers. The preparation and use of such materials in connection withcartilage replacement and repair is known.

In order to effect a therapeutic repair, a cavity 48 is formed in thebone tissue proximate to the location 42 of the body. The cavity 48 ispreferably sized to accept the middle portion 20 and the second end 18of the anchor 12 in a relatively tight fit. Preferably, the cavity 48has a length exceeding its diameter. The diameter of the cavity 48 maysuitably be on the order of 1 mm to 2 mm (pre-taper) for use in humanapplications. The cavity 48 may be formed with using a pin, not shown,inserted and manipulated arthroscopically. The pin diameter should beapproximately equal to or slightly smaller than the diameter of theanchor 12.

In a preferred operation, the soft tissue repair material 44 is disposedin the location 42 at the same time that the fixation device 10 issecured to the bone tissue 46. However, it will be noted that the softtissue repair material 44 may be disposed in the location 42 beforeinsertion of the fixation device 10 and, in some cases, prior to formingthe cavity 48.

Returning to the preferred operation, a core 49 is formed in the softtissue repair material 44 prior to insertion. The core 49 is sized toreceive anchor 12 of the fixation device 10. Coring the repair material44 avoids potential damage caused by a forced insertion of the secondend 18 and middle portion 20 of the anchor 12 through the repairmaterial 44. Once cored, the soft tissue repair material 44 is insertedonto the anchor 12, and the anchor 12 is inserted onto a pin, not shown,which is sized to fit through the channel 24. The anchor 12 and softtissue repair material 44 may then be advanced along the pin through acannula or the like to the location 42. The pin may be used as is wellknown in the art to guide the anchor 12 to the cavity 48. A slidehammer, not shown, may then be used to advance the second end 18 of theanchor 12 into the cavity 48 while the repair material 44 is trapped orretained in the location 42 by the material retention member 14.

In any event, the anchor 12 is advanced forward into the cavity 38 untilthe raised ribs 22 are disposed at least partially within the cavity 38.The raised ribs 22 and the bone tissue 46 cooperatively deform to forman interlock therebetween. The interlock assists in resistinginadvertent dislodge of the anchor 12. Moreover, as the bone tissue 46heals, it will grow into cavities formed by successive raised ribs 22,thereby further decreasing the possibility of inadvertent dislodge.However, it will be noted that the raised ribs 22 are not necessary toachieve attachment of the repair material 44 via the fixation device 10.An anchor comprised of a non-ribbed shaft provides a secure attachmentto the bone tissue through frictional forces. Nevertheless, theinclusion of the raised ribs 22 increase the robustness of theattachment for the reasons discussed above.

Thus, the present invention provides a reliable method of affixing softtissue repair material to a location of the body under theurapeuticrepair. Specifically, the use of a material retention member thatengages the repair material 44 in a plurality of directions provides anincreased and dispersed surface area of the repair material 44 that issubject to the retention force. Such dispersion of the surface areaunder retention force increases the ability to retain the repairmaterial 44 and avoid slip-through and dislodge of the repair material.It can be observed that the dispersion of the surface area of the repairmaterial under force may be increased by increasing the length of thespokes 26, 28, 30, and 32. However, excessive spoke length increases thepossibility of shearing the spokes 26, 28, 30 and 32. Spoke lengthsexceeding ¼^(th) of the length of the anchor 12, and preferably on theorder of ½^(th) of the length of the anchor 12 or more, provideadvantageous dispersion of the surface area of the repair material 44that is under force.

As discussed above, the fixation device 10 in at least some embodimentsis amenable to insertion using arthroscopic techniques and instruments.To this and other ends, the anchor 12 preferably has a length of on theorder of 12 mm to 20 mm. In a preferred embodiment, the length of thespoke 26 is preferably 6 mm to 8 mm, as measured from the center of theanchor 12.

In some circumstances, the quantity of soft tissue repair material, andmore particularly, the surface area of the repair material, exceeds thatwhich can be reasonably secured by a single fixation device. In suchcircumstances, a plurality of fixation devices similar to the fixationdevice may be employed in connection with a location under repair.

FIG. 3 shows a top plan view of a second exemplary embodiment of anassembly 50 for affecting therapeutic repairs wherein the amount ofrepair material 52 exceeds that which may reasonably be secured using asingle fixation device. The assembly 50 includes a relatively largequantity (as opposed to the quantity shown in FIG. 2) of repair material52 and a plurality of fixation devices 54, 56, 58, and 60. The pluralityof fixation devices 54, 56, 58, and 60 may suitably have the structureof the fixation device 10 of FIG. 1 as well as any other fixation deviceaccording to the present invention. Each of the plurality of fixationdevices 54, 56, 58 and 60 are inserted into cavities similar to thecavity 48. It is readily apparent that as many or as few fixationdevices may be employed as is necessary to achieve an appropriate amountof retention strength.

It is noted that other embodiments of a fixation device according to thepresent invention may provide alternative or additional benefits. Forexample, FIG. 4 shows a second exemplary embodiment of a fixation device110 according to the present invention. The fixation device 110 includesan anchor 112 similar to the anchor 12 of FIG. 1 and a materialretention member 114. The anchor 112, similar to the anchor 12, includesa first end 116 and a second end 118.

The material retention member 114 of the second exemplary embodiment ofthe fixation device 110 includes first and second spokes 120 and 122which extend in opposing radial directions. Each of the first and secondspokes 120 and 122 terminates at a connection point to a loop member124. The loop member 124, which in the exemplary embodiment describedherein is in the form of a circular ring, extends around the first end116. The loop member 124 includes a contact surface 126 whichcorresponding extends around the first end 116. The loop member furtherincludes a plurality of spikes 128 extending downward from the contactsurface 126.

One advantage of the loop member 124 is that the pressure points exertedby the material retention member 114 form a continuous loop, as opposedto discontinuous points, which further decreases the potential oftearing the repair material, not shown. Consistent with the embodimentdescribed above, the length of the spokes 120 and 122 (and thus theradius of the loop member 124) is preferably between ¼^(th) and ½^(th)of the length of the anchor 112.

In some circumstances, the bone tissue at the location of the body inwhich the repair must be effectuated is concave in shape. As such, it isadvantageous to provide a fixation device having a material retentiondevice that extends in a generally convex manner with respect to therepair material so that it conforms to the shape of the underlying bonetissue.

To this end, FIG. 5 shows a side plan view of a third exemplaryembodiment of a fixation device 210 according to the present inventionwhich incorporates a convex material retention device 214. Again, thefixation device 210 includes an anchor 212 and the material retentionmember 214. The anchor 212 has a first end 216 and a second end 218. Thematerial retention member 214 extends radially in a plurality ofdirections from the first end 216 of the anchor 212 and furthermoreextends at a non-normal angle upward with respect to an axis of theanchor portion.

The material retention member 214 of the exemplary embodiment of FIG. 5includes a plurality of spokes 226 and 228 (and typically will includemore, not shown in this view) that extend radially and angularly fromthe anchor in a plurality of directions. The overall shape of thematerial retention member 214 is convex with respect to second end 218.Each of the spokes 226 and 228 includes a contact surface 234 that isconfigured to contact the repair material to exert downward forcethereon. The contact surfaces 234 further include spike 236 extendingaxially therefrom.

FIG. 6 shows a side plan view of a fourth exemplary embodiment of afixation device 310 according to the present invention. The fixationdevice 310 is identical to the fixation device 210 except for thespokes. The fixation device 310 includes a plurality of spokes,including the spokes 326 and 328 shown in FIG. 6, which are individuallyconvex in shape from the point of view of the second end 318 of theanchor 312. The convex shape of the spokes 326 and 328 also helpaccommodate placement of the fixation device within concave shaped bonetissue.

FIG. 7 shows a side plan view of a fifth exemplary embodiment of afixation device 410 according to the present invention whichincorporates a concave material retention device 414. As above, thefixation device 410 includes an anchor 412 and the material retentionmember 414. The anchor 412 has a first end 416 and a second end 418. Thematerial retention member 414 extends radially in a plurality ofdirections from the first end 416 of the anchor 412 and furthermoreextends at a non-normal angle downward with respect to an axis of theanchor portion.

The material retention member 414 of the exemplary embodiment of FIG. 5includes a plurality of spokes 426 and 428 (and typically will includemore, not shown in this view) that extend radially and angularly fromthe anchor in a plurality of directions. The overall shape of thematerial retention member 414 is concave with respect to second end 418.Each of the spokes 426 and 428 includes a contact surface 434 that isconfigured to contact the repair material to exert downward forcethereon. The contact surfaces 434 further include spikes 436 extendingaxially therefrom.

The concave material retention member 414 may be used to accommodatelocations of the body under repair in which the relevant bone tissue isconvex in shape. Alternatively, the concave material retention member414 may be used as a spring bias force against the repair material wheninserted. In particular, when the fixation device 410 is inserted into acavity in bone tissue (see FIG. 2), the fixation device 410 may becontinually advanced into the cavity until the spokes 426 and 428 areelastically deformed or spring-biased backward. As such, the insertedfixation device 410 may suitably appear as the fixation device 10 ofFIG. 2, in other words, such that the spokes 426 and 428 extend in thenormal plane with respect to the anchor, when fully inserted. In such acase, the fixation device 410 will exhibit a greater retention force onthe repair material as a result of the spring bias of the spokes 426 and428.

Another embodiment that provides many of the advantages discussed abovein connection with the fixation device 410 are provided by the fixationdevice 510 of FIG. 8. FIG. 8 shows a side plan view of a sixth exemplaryembodiment of a fixation device 510 according to the present invention.

The fixation device 510 is identical to the fixation device 410 exceptfor the spokes. The fixation device 510 includes a plurality of spokes,including the spokes 526 and 528 shown in FIG. 8, which are individuallyconcave in shape from the point of view of the second end 518 of theanchor 512. The convex shape of the spokes 526 and 528 helps accommodateplacement of the fixation device 510 within convex shaped bone tissue,and/or provides additional retention force via spring biasing.

FIG. 9 shows a perspective view of a seventh exemplary embodiment of afixation device 610 according to the present invention that includes asubstantially disk-shaped material retention member 614. The disk-shapedmaterial retention member 614 provides similar advantages as thosediscussed above in connection with the loop member 124 of the fixationdevice 110 of FIG. 4. In an alternative embodiment, the top surface ofthe disk-shaped material retention member 614 may be convex or otherwiseshaped to accommodated bone geometry in the location under repair.Specifically, the retention force exerted by the material retentionmember 610 is dispersed in a continuous manner.

In general, the fixation device 610 includes an anchor 612 and thematerial retention member 614. The anchor 612 has a first end 616 and asecond end 618. The material retention member 614 comprises a disk thatextends radially in a plurality of directions from the first end 616 ofthe anchor 612. The material retention member 614 includes a contactsurface 634 that contacts the repair material (see FIG. 2) to exertdownward force thereon. The contact surface 634 further includes aplurality of spikes 636 extending axially therefrom.

FIG. 10 shows a side plan view of an eighth exemplary embodiment of afixation device 710 according to the present invention that provides twoalternative advantages relating to resisting rotation and insertion ofthe fixation device into the repair material. FIG. 11 shows a sidecutaway view of a third exemplary embodiment of an assembly 740 foreffecting therapeutic repairs that includes the fixation device 710 ofFIG. 10 shown implemented in a location 742 of a body that is undertherapeutic repair. In general, the assembly 740 includes a quantity ofsoft tissue repair material 744 and the fixation device 710.

In general, the fixation device 710 includes an anchor 712 and amaterial retention member 714. The anchor 712 has a first end 716 and asecond end 718. The material retention member 714 extends radially in aplurality of directions from the first end 716 of the anchor 712 and isconfigured to exert a retention force on repair material 744 that isinterposed between the material retention member 714 and bone tissue 746of a body.

In further detail, the anchor 712 of the exemplary embodiment of FIG. 10is in the form of a shaft and includes a center portion 720. The centerportion 720 includes a plurality of raised ribs 722. In particular, eachof the plurality of raised ribs 722 extends axially or longitudinallyalong an outer surface of the center portion 720 of the anchor 720. Thelongitudinally disposed raised ribs 722 cooperate with the bone tissue746 to form an interlock that resists rotation of the fixation device710.

The anchor 712 is slightly chamfered at the second end 718. As above,the anchor 712 may suitably be cannulated, thereby forming a channel 724within the anchor 712 that runs essentially the length of the anchor712.

The anchor 712 furthermore includes a shoulder 752 that is has a radiusthat is wider than the center portion 720. The larger radius of theshoulder 752 forms a shelf surface 754 at the intersection of theshoulder and the center portion 720 that faces toward the second end 718of the anchor 712. The shelf surface 754 provides a mechanism by whichinsertion of the anchor 712 may be stopped (see FIG. 11). As a result,the anchor 712 may be more precisely located at a particular depthwithin the bone tissue 746.

The material retention member 714 of the exemplary embodiment of FIG. 10may suitably have a structure similar to that describe above inconnection with any of the material retention members 14, 114, 214, 314,414, 514 or 614.

It will be appreciated that the above described embodiments are merelyexemplary, and that those of ordinary skill in the art may readilydevise their own implementations of the present invention thatincorporate the principles of the present invention and fall within thespirit and scope thereof. For example, the exact number of spokes in thevarious fixation devices need not be as shown in the exemplaryembodiments discussed herein. Likewise, it is noted that at least someof the advantages of the raised ribs 22 and 722 described above mayenjoyed in embodiments in which the raised ribs are raised from a centerportion of the anchor that is narrower than the remainder of the anchor.In other words, the raised ribs and the remainder of the anchor formrecessed channels between the raised ribs in the center portion. In suchembodiments, the raised ribs may be created by merely removing materialfrom the center portion of a smooth anchor shaft.

1. A method of effecting therapeutic reparation of a location of a bodycomprising: a) disposing soft tissue repair material in the location ofthe body; and b) securing an anchor of a fixation device into a cavityin bone tissue proximate the location of the body, the anchor having afirst end and a second end, the anchor further having an exteriorsurface including one or more raised ribs, and further the one or moreraised ribs are each oriented in a direction parallel to an axis of theanchor, the fixation device further comprising a material retentionmember extending radially from the anchor in a plurality of directions,such that at least one contact surface of the material retention memberengages a portion of the soft tissue repair material that is interposedbetween the material retention device and the bone tissue, wherein theanchor includes a shoulder portion extending from a location on theanchor between the first and second end toward a location proximate thefirst end of the anchor, and wherein step b) further comprises securingthe anchor within the cavity by advancing the anchor into the cavityuntil at least a portion of the shoulder contacts the bone tissue.
 2. Anassembly for use in effecting therapeutic reparation of a location ofthe body comprising, the assembly comprising: a quantity of soft tissuerepair material; and a fixation device, the fixation device comprisingan anchor configured to be inserted into a cavity in bone tissue, theanchor having a first end and a second end; and a material retentionmember extending radially from the anchor in a plurality of directions,the material retention member including at least one contact surfaceengaging at least a portion of the quantity of soft tissue repairmaterial, wherein the anchor further comprises raised ribs extendingfrom an outer surface thereof, wherein the one or more raised ribs eachextend along the outer surface of the anchor, and wherein the one ormore raised ribs are each oriented in a direction parallel to an axis ofsaid anchor, wherein said anchor includes a shoulder positioned adjacentto said material retention member, and wherein said one or more raisedribs extend downwardly from said shoulder.
 3. An assembly for use ineffecting therapeutic reparation of a location of the body comprising,the assembly comprising: a quantity of soft tissue repair material; anda fixation device, the fixation device comprising an anchor configuredto be inserted into a cavity in bone tissue, the anchor having a firstend and a second end; and a material retention member extending radiallyfrom the anchor in a plurality of directions, the material retentionmember including at least one contact surface engaging at least aportion of the quantity of soft tissue repair material, wherein theanchor further comprises raised ribs extending from an outer surfacethereof, wherein the one or more raised ribs each extend along the outersurface of the anchor, wherein the one or more raised ribs are eachoriented in a direction parallel to an axis of said anchor, wherein saidanchor includes a shoulder positioned adjacent to said materialretention member, wherein said anchor has a distal end, and wherein saidone or more raised ribs extend downwardly from said shoulder to alocation spaced apart from said distal end of said anchor.
 4. Anassembly for use in effecting therapeutic reparation of a location ofthe body comprising, the assembly comprising: a quantity of soft tissuerepair material; and a fixation device, the fixation device comprisingan anchor configured to be inserted into a cavity in bone tissue, theanchor having a first end and a second end; and a material retentionmember extending radially from the anchor in a plurality of directions,the material retention member including at least one contact surfaceengaging at least a portion of the quantity of soft tissue repairmaterial, wherein the anchor further comprises raised ribs extendingfrom an outer surface thereof, wherein the one or more raised ribs eachextend along the outer surface of the anchor, wherein the one or moreraised ribs are each oriented in a direction parallel to an axis of saidanchor, wherein said anchor includes a shoulder positioned adjacent tosaid material retention member, wherein said anchor has a distal end,wherein said one or more raised ribs extend downwardly from saidshoulder to a location spaced apart from said distal end of said anchor,wherein said anchor possesses a length L1, and wherein each of said oneor more raised ribs possesses a length L2, and wherein L2≧(0.75)L1.
 5. Amethod of effecting therapeutic reparation of a location of a bodycomprising: a) disposing soft tissue repair material in the location ofthe body; and b) securing an anchor of a fixation device into a cavityin bone tissue proximate the location of the body, the anchor having afirst end and a second end, the anchor further having an exteriorsurface including one or more raised ribs, and further the one or moreraised ribs are each oriented in a direction parallel to an axis of theanchor, the fixation device further comprising a material retentionmember extending radially from the anchor in a plurality of directions,such that at least one contact surface of the material retention memberengages a portion of the soft tissue repair material that is interposedbetween the material retention device and the bone tissue, wherein saidanchor includes a shoulder positioned adjacent to said materialretention member, wherein said anchor has a dial end, and wherein saidone or more raised ribs extend downwardly from said shoulder to alocation spaced apart from said distal end of said anchor.
 6. A methodof effecting therapeutic reparation of a location of a body comprising:a) disposing soft tissue repair material in the location of the body;and b) securing an anchor of a fixation device into a cavity in bonetissue proximate the location of the body, the anchor having a first endand a second end, the anchor further having an exterior surfaceincluding one or more raised ribs, and further the one or more raisedribs are each oriented in a direction parallel to an axis of the anchor,the fixation device further comprising a material retention memberextending radially from the anchor in a plurality of directions, suchthat at least one contact surface of the material retention memberengages a portion of the soft tissue repair material that is interposedbetween the material retention device and the bone tissue, wherein saidanchor includes a shoulder positioned adjacent to said materialretention member, wherein said anchor has a distal end, wherein said oneor more raised ribs extend downwardly from said shoulder to a locationspaced apart from said distal end of said anchor, wherein said anchorpossesses a length L1, and wherein each of said one or more raised ribspossesses a length L2, and wherein L2≧(0.75)L1.